1. Field
Embodiments of the present invention relate to a three-dimensional (3D) image display device, and more particularly, to a 3D image display device embodying 3D images by forming a plurality of images with different depths by using a hologram element.
2. Description of the Related Art
Three-dimensional (3D) image display devices can present images with more reality and efficiency, and thus are demanded in fields such as medical imaging, video games, advertisement, education, the military, etc. Thus, methods of embodying 3D images such as holography or stereoscopy are being developed widely.
The holography method involves recording interference signals obtained by overlapping light from the subject of an image and reference light with coherency and reproducing the recorded interference signals, and is an ultimate method for displaying 3D images. However, the method requires a massive capacity of data, and peripheral technologies such as signal processing are not secured yet.
The stereoscopy method involves separately showing two-dimensional (2D) images with a binocular parallax to the left eye and the right eye of a viewer such that the images are shown as 3D images. For example, a stereoscopic 3D image display device employs a liquid crystal display (LCD) panel, in which the left-eye pixels for displaying image information for the left eye and the right-eye pixels for displaying image information for the right eye are alternately formed, and a parallax barrier for separating images for the left eye and images for the right eye such that the images are respectively shown to the left eye and the right eye. According to the stereoscopy method, a 3D image display device can be configured with a flat-panel display panel and simple optical elements, and thus, using a slim 3D image display device can embody 3D images. However, since images for the left eye and images for the right eye are required to be displayed on a single panel, the resolution of images is reduced to 50% or less and eye fatigue may occur easily. Furthermore, it is not easy to embody 2D images together with 3D images owing to the structure such that left eye images and right eye images are displayed on a single panel.
There is a method of presenting actual depth by using a plurality of display panels. However, using a plurality of display planes not only increases the size of a 3D image display system, but also increases the manufacturing cost of the system.